Capital Dynamics backs £100m energy storage project in Northern Ireland

Global private asset manager Capital Dynamics has partnered with Solo Renewables to deliver a potential £100m (€115m) long-duration energy storage system (LDES) in Northern Ireland.

Located in Islandmagee, the 150MW project is designed to provide up to eight hours of storage capacity and, once operational, will be capable of supplying the daily energy needs of up to 36,000 households.

The project received planning approval from Mid and East Antrim Borough Council in February 2026, within six months of the initial submission.

Barney Coles

Barney Coles, senior managing director and co-head of clean energy at Capital Dynamics, said: “Long-duration storage has a critical role to play in supporting Northern Ireland’s energy transition and is a fast and efficient way to strengthen grid resilience as renewable generation continues to grow.

“Projects such as this can provide additional flexibility to help manage renewable variability, support grid stability and improve the overall efficiency of the electricity system.”

The deal is indicative of a new investment trend with developers and capital are moving beyond 2–4 hour BESS toward long-duration (8-hour) systems to solve curtailment and grid saturation, not just volatility.

This aligns with broader market behaviour where investors increasingly prioritise grid-ready, flexibility-driven assets over pure generation capacity.

Northern Ireland is now facing rising renewable penetration, particularly wind, alongside growing curtailment rates. Short-duration BESS has supported ancillary services but cannot absorb excess generation at scale. The Islandmagee project directly targets this gap by enabling multi-hour shifting of surplus power.

Commercially, this signals a shift in value capture. Storage is no longer just about frequency response or short-cycle trading - it is becoming critical infrastructure for renewable integration. Markets with policy support, such as the Renewable Electricity Price Guarantee (REPG), are accelerating this transition by de-risking investment.

More importantly, deal structures are evolving. Instead of standalone project sales, capital is entering through partnerships at development stage, mirroring the global trend toward platform-style investments and co-development structures seen across BESS markets.

This project signals that long-duration storage is moving from pilot-scale to bankable infrastructure, particularly in constrained grids where renewable growth is outpacing flexibility.

Interest continues to grow in LDES in Northern Ireland Image: Highview and Andrew Hutchinson

Andrew Hutchinson, director at Solo Renewables, said: “Securing planning approval in six months reflects the strength of this project and the local understanding that Islandmagee is one of the most strategically important locations in the all-island energy network.

“Northern Ireland has great potential to create and use more renewable electricity locally. This will be a good thing for homes and businesses across the region but can only happen if we increase our ability to store wind and solar energy that can’t be used at the time it’s produced.”